1. Field of the Invention
This invention relates to processors. More specifically, this invention relates to processors implementing a system management mode of operation.
2. Description of the Related Art
System management mode (SMM) is a processor operating mode for performing high level systems functions such as power management or security functions.
Different microprocessor manufacturers have implemented SMM systems differently so that some SMM functionality is standard or semi-standard and other functionality is very different. A primary constant feature in different SMM implementations is that the high level functions operating under SMM, and the underlying SMM operations, are transparent both to operating systems and application software. Another common characteristic of various SMM implementations is that SMM functionality is hardcoded into the processor integrated circuit chip and, thus, is permanently fixed.
One problem with the conventional, hardcoded SMM implementation is that differences in SMM implementations by various processor manufacturers give rise to incompatibilities in functionality for processor chips that are otherwise designed for compatibility. A second problem is that the hardcoded SMM implementation may be highly advantageous for some applications, but disadvantageous for other applications. For example, a full-functionality but high overhead SMM implementation may be desired in some applications while a reduced-functionality, low overhead implementation is better suited in other applications. Another problem is that some computer system integrators wish to implement special-purpose or proprietary SMM functionality.